Photoresist composition and method of forming photoresist pattern

ABSTRACT

Method of forming pattern in photoresist layer includes forming photoresist layer over substrate, selectively exposing photoresist layer to actinic radiation forming latent pattern. Latent pattern is developed by applying developer to form pattern. Photoresist layer includes photoresist composition including polymer:A1, A2, L are direct bond, C4-C30 aromatic, C4-C30 alkyl, C4-C30 cycloalkyl, C4-C30 hydroxylalkyl, C4-C30 alkoxy, C4-C30 alkoxyl alkyl, C4-C30 acetyl, C4-C30 acetylalkyl, C4-C30 alkyl carboxyl, C4-C30 cycloalkyl carboxyl, C4-C30 hydrocarbon ring, C4-C30 heterocyclic, —COO—, A1 and A2 are not both direct bonds, and are unsubstituted or substituted with a halogen, carbonyl, or hydroxyl; A3 is C6-C14 aromatic, wherein A3 is unsubstituted or substituted with halogen, carbonyl, or hydroxyl; R1 is acid labile group; Ra, Rb are H or C1-C3 alkyl; Rf is direct bond or C1-C5 fluorocarbon; PAG is photoacid generator; 0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/041,070, filed Jun. 18, 2020, the entire disclosure of which isincorporated herein by reference.

BACKGROUND

As consumer devices have gotten smaller and smaller in response toconsumer demand, the individual components of these devices havenecessarily decreased in size as well. Semiconductor devices, which makeup a major component of devices such as mobile phones, computer tablets,and the like, have been pressured to become smaller and smaller, with acorresponding pressure on the individual devices (e.g., transistors,resistors, capacitors, etc.) within the semiconductor devices to also bereduced in size.

One enabling technology that is used in the manufacturing processes ofsemiconductor devices is the use of photolithographic materials. Suchmaterials are applied to a surface of a layer to be patterned and thenexposed to an energy that has itself been patterned. Such an exposuremodifies the chemical and physical properties of the exposed regions ofthe photosensitive material. This modification, along with the lack ofmodification in regions of the photosensitive material that were notexposed, can be exploited to remove one region without removing theother.

However, as the size of individual devices has decreased, processwindows for photolithographic processing has become tighter and tighter.As such, advances in the field of photolithographic processing arenecessary to maintain the ability to scale down the devices, and furtherimprovements are needed in order to meet the desired design criteriasuch that the march towards smaller and smaller components may bemaintained.

As the semiconductor industry has progressed into nanometer technologyprocess nodes in pursuit of higher device density, higher performance,and lower costs, there have been challenges in reducing semiconductorfeature size. Extreme ultraviolet lithography (EUVL) has been developedto form smaller semiconductor device feature size and increase devicedensity on a semiconductor wafer. In order to improve EUVL an increasein wafer exposure throughput is desirable. Wafer exposure throughput canbe improved through increased exposure power or increased resistphotospeed. Low exposure dose may lead to increased line width roughnessand reduced critical dimension uniformity.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 illustrates a process flow of manufacturing a semiconductordevice according to embodiments of the disclosure.

FIG. 2 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 3A and 3B show a process stage of a sequential operation accordingto an embodiment of the disclosure.

FIG. 4 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 5 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 6 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 7 shows a polymer for a photoresist composition according toembodiments of the disclosure.

FIG. 8 shows a polymer for a photoresist composition according toembodiments of the disclosure.

FIGS. 9A, 9B, and 9C show polymers for photoresist compositionsaccording to embodiments of the disclosure.

FIGS. 10A, 10B, and 10C show polymers for photoresist compositionsaccording to embodiments of the disclosure.

FIGS. 11A, 11B, 11C, and 11D show polymers for photoresist compositionsaccording to embodiments of the disclosure.

FIG. 12 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 13A and 13B show a process stage of a sequential operationaccording to an embodiment of the disclosure.

FIG. 14 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 15 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 16 shows a process stage of a sequential operation according to anembodiment of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

FIG. 1 illustrates a process flow 100 of manufacturing a semiconductordevice according to embodiments of the disclosure. A photoresist iscoated on a surface of a layer to be patterned or a substrate 10 inoperation S110, in some embodiments, to form a photoresist layer 15, asshown in FIG. 2. Then the photoresist layer 15 undergoes a first bakingoperation S120 to evaporate solvents in the photoresist composition insome embodiments. The photoresist layer 15 is baked at a temperature andtime sufficient to cure and dry the photoresist layer 15. In someembodiments, the photoresist layer is heated to a temperature of about40° C. and 120° C. for about 10 seconds to about 10 minutes.

After the first baking operation S120, the photoresist layer 15 isselectively exposed to actinic radiation 45/97 (see FIGS. 3A and 3B) inoperation S130. In some embodiments, the photoresist layer 15 isselectively exposed to ultraviolet radiation. In some embodiments, theultraviolet radiation is deep ultraviolet radiation (DUV). In someembodiments, the ultraviolet radiation is extreme ultraviolet (EUV)radiation. In some embodiments, the radiation is an electron beam.

As shown in FIG. 3A, the exposure radiation 45 passes through aphotomask 30 before irradiating the photoresist layer 15 in someembodiments. In some embodiments, the photomask has a pattern to bereplicated in the photoresist layer 15. The pattern is formed by anopaque pattern 35 on the photomask substrate 40, in some embodiments.The opaque pattern 35 may be formed by a material opaque to ultravioletradiation, such as chromium, while the photomask substrate 40 is formedof a material that is transparent to ultraviolet radiation, such asfused quartz.

In some embodiments, the selective exposure of the photoresist layer 15to form exposed regions 50 and unexposed regions 52 is performed usingextreme ultraviolet lithography. In an extreme ultraviolet lithographyoperation a reflective photomask 65 is used to form the patternedexposure light, as shown in FIG. 3B. The reflective photomask 65includes a low thermal expansion glass substrate 70, on which areflective multilayer 75 of Si and Mo is formed. A capping layer 80 andabsorber layer 85 are formed on the reflective multilayer 75. A rearconductive layer 90 is formed on the back side of the low thermalexpansion substrate 70. In extreme ultraviolet lithography, extremeultraviolet radiation 95 is directed towards the reflective photomask 65at an incident angle of about 6°. A portion 97 of the extremeultraviolet radiation is reflected by the Si/Mo multilayer 75 towardsthe photoresist-coated substrate 10, while the portion of the extremeultraviolet radiation incident upon the absorber layer 85 is absorbed bythe photomask. In some embodiments, additional optics, includingmirrors, are between the reflective photomask 65 and thephotoresist-coated substrate.

The region of the photoresist layer exposed to radiation 50 undergoes achemical reaction thereby changing its solubility in a subsequentlyapplied developer relative to the region of the photoresist layer notexposed to radiation 52. In some embodiments, the portion of thephotoresist layer exposed to radiation 50 undergoes a crosslinkingreaction.

Next, the photoresist layer 15 undergoes a post-exposure bake inoperation S140. In some embodiments, the photoresist layer 15 is heatedto a temperature of about 50° C. and 160° C. for about 20 seconds toabout 10 minutes. In some embodiments, the photoresist layer 15 isheated for about 30 seconds to about 5 minutes. In some embodiments, thephotoresist layer 15 is heated for about 1 minute to about 2 minutes.The post-exposure baking may be used in order to assist in thegenerating, dispersing, and reacting of the acid/base/free radicalgenerated from the impingement of the radiation 45/97 upon thephotoresist layer 15 during the exposure. Such assistance helps tocreate or enhance chemical reactions, which generate chemicaldifferences between the exposed region 50 and the unexposed region 52within the photoresist layer. These chemical differences also causedifferences in the solubility between the exposed region 50 and theunexposed region 52.

The selectively exposed photoresist layer is subsequently developed byapplying a developer to the selectively exposed photoresist layer inoperation S150. As shown in FIG. 4, a developer 57 is supplied from adispenser 62 to the photoresist layer 15. In some embodiments where thephotoresist is a positive-tone photoresist, the exposed portion of thephotoresist layer 50 is removed by the developer 57 forming a pattern ofopenings 55 in the photoresist layer 15 to expose the substrate 10, asshown in FIG. 5.

In some embodiments, the pattern of openings 55 in the photoresist layer15 are extended into the layer to be patterned or substrate 10 to createa pattern of openings 55′ in the substrate 10, thereby transferring thepattern in the photoresist layer 15 into the substrate 10, as shown inFIG. 6. The pattern is extended into the substrate by etching, using oneor more suitable etchants. The unexposed photoresist layer 15 is atleast partially removed during the etching operation in someembodiments. In other embodiments, the unexposed photoresist layer 15 isremoved after etching the substrate 10 by using a suitable photoresiststripper solvent or by a photoresist ashing operation.

In some embodiments, the substrate 10 includes a single crystallinesemiconductor layer on at least it surface portion. The substrate 10 mayinclude a single crystalline semiconductor material such as, but notlimited to Si, Ge, SiGe, GaAs, InSb, GaP, GaSb, InAlAs, InGaAs, GaSbP,GaAsSb and InP. In some embodiments, the substrate 10 is a silicon layerof an SOI (silicon-on insulator) substrate. In certain embodiments, thesubstrate 10 is made of crystalline Si.

The substrate 10 may include in its surface region, one or more bufferlayers (not shown). The buffer layers can serve to gradually change thelattice constant from that of the substrate to that of subsequentlyformed source/drain regions. The buffer layers may be formed fromepitaxially grown single crystalline semiconductor materials such as,but not limited to Si, Ge, GeSn, SiGe, GaAs, InSb, GaP, GaSb, InAlAs,InGaAs, GaSbP, GaAsSb, GaN, GaP, and InP. In an embodiment, the silicongermanium (SiGe) buffer layer is epitaxially grown on the siliconsubstrate 10. The germanium concentration of the SiGe buffer layers mayincrease from 30 atomic % for the bottom-most buffer layer to 70 atomic% for the top-most buffer layer.

In some embodiments, the substrate 10 includes one or more layers of atleast one metal, metal alloy, and metal/nitride/sulfide/oxide/silicidehaving the formula MX_(a), where M is a metal and X is N, S, Se, O, Si,and a is from about 0.4 to about 2.5. In some embodiments, the substrate10 includes titanium, aluminum, cobalt, ruthenium, titanium nitride,tungsten nitride, tantalum nitride, and combinations thereof.

In some embodiments, the substrate 10 includes a dielectric having atleast a silicon or metal oxide or nitride of the formula MX_(b), where Mis a metal or Si, X is N or O, and b ranges from about 0.4 to about 2.5.In some embodiments, the substrate 10 includes silicon dioxide, siliconnitride, aluminum oxide, hafnium oxide, lanthanum oxide, andcombinations thereof.

The photoresist layer 15 is a photosensitive layer that is patterned byexposure to actinic radiation. Typically, the chemical properties of thephotoresist regions struck by incident radiation change in a manner thatdepends on the type of photoresist used. Photoresist layers 15 areeither positive tone resists or negative tone resists. In someembodiments, the photoresist is a positive tone resist. A positive toneresist refers to a photoresist material that when exposed to radiation,such as UV light, becomes soluble in a developer, while the region ofthe photoresist that is non-exposed (or exposed less) is insoluble inthe developer. In other embodiments, the photoresist is a negative toneresist. A negative tone resist refers to a photoresist material thatwhen exposed to radiation becomes insoluble in the developer, while theregion of the photoresist that is non-exposed (or exposed less) issoluble in the developer. The region of a negative resist that becomesinsoluble upon exposure to radiation may become insoluble due to across-linking reaction caused by the exposure to radiation.

Whether a resist is a positive tone or negative tone may depend on thetype of developer used to develop the resist. For example, some positivephotoresists provide a positive pattern, (i.e.—the exposed regions areremoved by the developer), when the developer is an aqueous-baseddeveloper, such as a tetramethylammonium hydroxide (TMAH) solution. Onthe other hand, the same photoresist provides a negative pattern(i.e.—the unexposed regions are removed by the developer) when thedeveloper is an organic solvent, such as n-butyl acetate (nBA). Further,whether a resist is a positive or negative tone may depend on thepolymer. For example in some resists developed with the TMAH solution,the unexposed regions of the photoresist are removed by the TMAH, andthe exposed regions of the photoresist, that undergo cross-linking uponexposure to actinic radiation, remain on the substrate afterdevelopment.

In some embodiments, the photoresist composition includes a polymer,having the formula shown in FIG. 7. In some embodiments, the polymer hasa formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group. Insome embodiments, A₃ is a C6-C14 aromatic group, wherein A₃ isunsubstituted or substituted with a halogen, carbonyl group, or hydroxylgroup, R₁ is an acid labile group, Ra and Rb are independently H or aC1-C3 alkyl group, and R_(f) is a direct bond or a C1-C5 fluorocarbon.PAG is a photoacid generator, and 0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and0≤z/(x+y+z)≤1.

In some embodiments, A₁, A₂, and A₃ are independently a chain, ring, orthree-dimensional structure. In some embodiments, the three-dimensionalstructure is an adamantyl or norbornyl structure. In some embodiments,A₁, A₂, and A₃ are independently a phenyl group or a naphthalenyl group.In some embodiments, the A₁, A₂, and A₃ groups impart etching resistanceto the polymer.

In some embodiments, R₁ is a C4-C15 alkyl group, a C4-C15 cycloalkylgroup, a C4-C15 hydroxylalkyl group, a C4-C15 alkoxy group, or a C4-C15alkoxyl alkyl group. In some embodiments, R₁ is a tert-butyl group.

In some embodiments, R_(f) is a perfluorinated group.

In some embodiments, A₃ is a phenol group, a hydroxynaphthalene group,or a hydroxyanthracene group.

In some embodiments, the polymer has a weight average molecular weightranging from 500 to 1,000,000. In some embodiments, the polymer has aweight average molecular weight ranging from 2,000 to 250,000.

In some embodiments, L is a direct bond, A₃ is a p-phenol group, and0.2≤x/(x+y+z)≤0.5.

In some embodiments, A₁ is not a direct bond and 0.2≤y/(x+y+z)≤0.7. Insome embodiments, A₂ is not a direct bond and 0.05≤z/(x+y+z)≤0.5. Insome embodiments, 0.1≤x/(x+y+z)≤0.5. In some embodiments, A₁ and A₂ arenot direct bonds and 0.2≤y/(x+y+z)≤0.7 and 0.05≤z/(x+y+z)≤0.5. In someembodiments, A₁ is not a direct bond and 0.2≤y/(x+y+z)≤0.7 and0.1≤x/(x+y+z)≤0.5. In some embodiments, A₁ and A₂ are not direct bondsand 0.2≤y/(x+y+z)≤0.7, 0.05≤z/(x+y+z)≤0.5, and 0.1≤x/(x+y+z)≤0.5.

In some embodiments, the photoacid generator group PAG includes atriarylsulfonium group, diaryliodonium group, trifluoromethanesulfonategroup, or iodonium sulfonate group. In some embodiments, the photoacidgenerator group includes a triphenylsulfonium group and a sulfonategroup.

In some embodiments, the photoresist composition includes one or morephotoactive compounds (PAC) in addition to the PAG group attached to thepolymer or instead of the PAG group attached to the polymer.

In some embodiments, the PACs include photoacid generators, photobasegenerators, photo decomposable bases, free-radical generators, or thelike. In some embodiments in which the PACs are photoacid generators,the PACs include halogenated triazines, onium salts, diazonium salts,aromatic diazonium salts, phosphonium salts, sulfonium salts, iodoniumsalts, imide sulfonate, oxime sulfonate, diazodisulfone, disulfone,o-nitrobenzylsulfonate, sulfonated esters, halogenated sulfonyloxydicarboximides, diazodisulfones, α-cyanooxyamine-sulfonates,imidesulfonates, ketodiazosulfones, sulfonyldiazoesters,1,2-di(arylsulfonyl)hydrazines, nitrobenzyl esters, and the s-triazinederivatives, combinations of these, or the like.

Specific examples of photoacid generators includeα-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarb-o-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates, hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl)sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl)triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, α,α′-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, or the like.

In some embodiments in which the PACs are free-radical generators, thePACs include n-phenylglycine; aromatic ketones, including benzophenone,N,N′-tetramethyl-4,4′-diaminobenzophenone,N,N′-tetraethyl-4,4′-diaminobenzophenone,4-methoxy-4′-dimethylaminobenzo-phenone,3,3′-dimethyl-4-methoxybenzophenone,p,p′-bis(dimethylamino)benzo-phenone,p,p′-bis(diethylamino)-benzophenone; anthraquinone,2-ethylanthraquinone; naphthaquinone; and phenanthraquinone; benzoinsincluding benzoin, benzoinmethylether, benzoinisopropylether,benzoin-n-butylether, benzoin-phenylether, methylbenzoin andethylbenzoin; benzyl derivatives, including dibenzyl,benzyldiphenyldisulfide, and benzyldimethylketal; acridine derivatives,including 9-phenylacridine, and 1,7-bis(9-acridinyl)heptane;thioxanthones, including 2-chlorothioxanthone, 2-methylthioxanthone,2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, and2-isopropylthioxanthone; acetophenones, including1,1-dichloroacetophenone, p-t-butyldichloro-acetophenone,2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and2,2-dichloro-4-phenoxyacetophenone; 2,4,5-triarylimidazole dimers,including 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer,2-(o-chlorophenyl)-4,5-di-(m-methoxyphenyl imidazole dimer,2-(o-fluorophenyl)-4,5-diphenylimidazole dimer,2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer,2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer,2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer,2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer and2-(p-methylmercaptophenyl)-4,5-diphenylimidazole dimmer; combinations ofthese, or the like.

In some embodiments, the photoresist composition includes a photoactivecompound, wherein A₁ is not a direct bond and 0.2≤y/(x+y+z)≤0.7. In someembodiments, the photoresist composition includes a photoactive compoundand 0.1≤x/(x+y+z)≤0.5. In some embodiments, the photoresist compositionincludes a photoactive compound, wherein A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5.

The R₁ group on the polymer decomposes or is cleaved when exposed to theacid generated by the PAG group, or to an acid, base, or free radicalgenerated by the PAC. If the R₁ is decomposed or cleaved by an acid, itis known as an acid labile group (ALG). In some embodiments, the R₁group which will decompose is a carboxylic acid group, a fluorinatedalcohol group, a phenolic alcohol group, a sulfonic group, a sulfonamidegroup, a sulfonylimido group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (alkylsulfonyl)(alkyl-carbonyl)imidogroup, a bis(alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imidogroup, a bis(alkylsylfonyl)methylene group, a bis(alkylsulfonyl)imidogroup, a tris(alkylcarbonyl methylene group, atris(alkylsulfonyl)methylene group, combinations of these, or the like.Specific groups that are used for the fluorinated alcohol group includefluorinated hydroxyalkyl groups, such as a hexafluoroisopropanol groupin some embodiments. Specific groups that are used for the carboxylicacid group include acrylic acid groups, methacrylic acid groups, or thelike.

As one of ordinary skill in the art will recognize, the chemicalcompounds listed herein are merely intended as illustrated examples ofthe PACs and are not intended to limit the embodiments to only thosePACs specifically described. Rather, any suitable PAC may be used, andall such PACs are fully intended to be included within the scope of thepresent embodiments.

FIG. 8 shows a polymer for a photoresist composition according to someembodiments of the disclosure. As shown in FIG. 8, L is a direct bond,A₃ is a p-phenol group, and the PAG group includes a sulfonate anion anda triphenyl sulfonium cation.

FIGS. 9A, 9B, and 9C show polymers for photoresist compositionsaccording to embodiments of the disclosure. In FIG. 9A, the etchingresistance of the polymer is improved when A₁ is a phenyl group, whilein FIG. 9B the etching resistance of the polymer is improved when A₂ isa phenyl group. While in some embodiments, as shown in FIG. 9C, improvedetching resistance is provided when both A₁ and A₂ are phenyl groups.

FIGS. 10A, 10B, and 10C show polymers for photoresist compositionsaccording to embodiments of the disclosure. In FIG. 10A, etchingresistance of the polymer is improved when A₁ is a naphthalenyl group,while in FIG. 10B the etching resistance of the polymer is improved whenA₂ is a naphthalenyl group. While in some embodiments, as shown in FIG.10C, improved etching resistance is provided when both A₁ and A₂ arenaphthalenyl groups.

FIGS. 11A, 11B, 11C, and 11D show polymers for photoresist compositionsaccording to embodiments of the disclosure. In FIG. 11A, the etchingresistance of the polymer is improved when L is direct bond and A₃ is ahydroxynaphthalenyl group, while in FIG. 11B the etching resistance ofthe polymer is improved when L is a direct bond and A₃ is ahydroxyanthracenyl group. In some embodiments, as shown in FIG. 11C,improved etching resistance is provided when L is a —COO— group and A₃is a hydroxynaphthalenyl group, while in some embodiments, as shown inFIG. 11D, improved etching resistance is provided when L is a —COO—group and A₃ is a hydroxyanthracenyl group.

In some embodiments, photoresist compositions according to the presentdisclosure include a metal oxide nanoparticle and one or more organicligands. In some embodiments, the metal oxide nanoparticle is anorganometallic including one or more metal oxide nanoparticles selectedfrom the group consisting of titanium dioxide, zinc oxide, zirconiumdioxide, nickel oxide, cobalt oxide, manganese oxide, copper oxides,iron oxides, strontium titanate, tungsten oxides, vanadium oxides,chromium oxides, tin oxides, hafnium oxide, indium oxide, cadmium oxide,molybdenum oxide, tantalum oxides, niobium oxide, aluminum oxide, andcombinations thereof. As used herein, nanoparticles are particles havingan average particle size between about 1 nm and about 20 nm. In someembodiments, the metal oxide nanoparticles have an average particle sizebetween about 2 nm and about 5 nm. In some embodiments, the amount ofmetal oxide nanoparticles in the photoresist composition ranges fromabout 1 wt. % to about 15 wt. % based on the weight of the firstsolvent. In some embodiments, the amount of nanoparticles in thephotoresist composition ranges from about 5 wt. % to about 10 wt. %based on the weight of the first solvent. Below about 1 wt. % metaloxide nanoparticles the photoresist coating is too thin. Above about 15wt. % metal oxide nanoparticles the photoresist coating is too thick.

In some embodiments, the metal oxide nanoparticles are complexed with aligand. In some embodiments, the ligand is a carboxylic acid or sulfonicacid ligand. For example, in some embodiments, zirconium oxide orhafnium oxide nanoparticles are complexed with methacrylic acid forminghafnium methacrylic acid (HfMAA) or zirconium (ZrMAA) methacrylic acid.In some embodiments, the metal oxide nanoparticles are complexed withligands including aliphatic or aromatic groups. The aliphatic oraromatic groups may be unbranched or branched with cyclic or noncyclicsaturated pendant groups containing 1-9 carbons, including alkyl groups,alkenyl groups, and phenyl groups. The branched groups may be furthersubstituted with oxygen or halogen.

In some embodiments, the photoresist composition includes about 0.1 wt.% to about 20 wt. % of the ligand. In some embodiments, the photoresistincludes about 1 wt. % to about 10 wt. % of the ligand. In someembodiments, the ligand concentration is about 10 wt. % to about 40 wt.% based on the weight of the metal oxide nanoparticles. Below about 10wt. % ligand the organometallic photoresist does not function well.Above about 40 wt. % ligand it is hard to form the photoresist layer. Insome embodiments, the ligand is HfMAA or ZrMAA dissolved at about a 5wt. % to about 10 wt. % weight range in a coating solvent, such aspropylene glycol methyl ether acetate (PGMEA).

In some embodiments, the polymer and any desired additives or otheragents, are added to the solvent for application. Once added, themixture is then mixed in order to achieve a homogenous compositionthroughout the photoresist to ensure that there are no defects caused byuneven mixing or nonhomogeneous composition of the photoresist. Oncemixed together, the photoresist may either be stored prior to its usageor used immediately.

The solvent can be any suitable solvent. In some embodiments, thesolvent is one or more selected from propylene glycol methyl etheracetate (PGMEA), propylene glycol monomethyl ether (PGME),1-ethoxy-2-propanol (PGEE), γ-butyrolactone (GBL), cyclohexanone (CHN),ethyl lactate (EL), methanol, ethanol, propanol, n-butanol, acetone,dimethylformamide (DMF), isopropanol (IPA), tetrahydrofuran (THF),methyl isobutyl carbinol (MIBC), n-butyl acetate (nBA), and 2-heptanone(MAK).

In some embodiments, the photoresist composition further includes waterat a concentration of 10 ppm to 250 ppm based on the total compositionof the water, any additives, and the solvent.

In some embodiments, the photoresist composition includes the polymeralong with one or more photoactive compounds (PACs). In someembodiments, the polymer includes one or more groups that will decompose(e.g., acid labile groups) or otherwise react when mixed with acids,bases, or free radicals generated by the PACs (as further describedbelow).

In some embodiments, the polymer also includes other groups attached tothe hydrocarbon structure that help to improve a variety of propertiesof the polymerizable resin. For example, inclusion of a lactone group tothe hydrocarbon structure assists to reduce the amount of line edgeroughness after the photoresist has been developed, thereby helping toreduce the number of defects that occur during development. In someembodiments, the lactone groups include rings having five to sevenmembers, although any suitable lactone structure may alternatively beused for the lactone group.

In some embodiments, the polymer includes groups that can assist inincreasing the adhesiveness of the photoresist layer 15 to underlyingstructures (e.g., substrate 10). Polar groups may be used to helpincrease the adhesiveness. Suitable polar groups include hydroxylgroups, cyano groups, or the like, although any suitable polar groupmay, alternatively, be used.

Optionally, the polymer includes one or more alicyclic hydrocarbonstructures that do not also contain a group, which will decompose insome embodiments. In some embodiments, the hydrocarbon structure thatdoes not contain a group which will decompose includes structures suchas 1-adamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate,cyclohexyl (methacrylate), combinations of these, or the like.

In some embodiments, the photoresist composition includes a quencher toinhibit diffusion of the generated acids/bases/free radicals within thephotoresist. The quencher improves the resist pattern configuration aswell as the stability of the photoresist over time. In an embodiment,the quencher is an amine, such as a second lower aliphatic amine, atertiary lower aliphatic amine, or the like. Specific examples of aminesinclude trimethylamine, diethylamine, triethylamine, di-n-propylamine,tri-n-propylamine, tripentylamine, diethanolamine, and triethanolamine,alkanolamine, combinations thereof, or the like.

In some embodiments, an organic acid is used as the quencher. Specificembodiments of organic acids include malonic acid, citric acid, malicacid, succinic acid, benzoic acid, salicylic acid; phosphorous oxo acidand its derivatives, such as phosphoric acid and derivatives thereofsuch as its esters, phosphoric acid di-n-butyl ester and phosphoric aciddiphenyl ester; phosphonic acid and derivatives thereof such as itsester, such as phosphonic acid dimethyl ester, phosphonic aciddi-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester,and phosphonic acid dibenzyl ester; and phosphinic acid and derivativesthereof such as its esters, including phenylphosphinic acid.

In some embodiments, the quenchers include photobase generators andphoto decomposable bases. In embodiments in which the quenchers arephotobase generators (PBG), the PBGs include quaternary ammoniumdithiocarbamates, a aminoketones, oxime-urethane containing moleculessuch as dibenzophenoneoxime hexamethylene diurethan, ammoniumtetraorganylborate salts, and N-(2-nitrobenzyloxycarbonyl)cyclic amines,combinations of these, or the like.

In some embodiments, the quencher is a photo decomposable bases (PBD),such as triphenylsulfonium hydroxide.

In some embodiments, a cross-linking agent is added to the photoresist.The cross-linking agent reacts with one group from one of thehydrocarbon structures in the polymer resin and also reacts with asecond group from a separate one of the hydrocarbon structures in orderto cross-link and bond the two hydrocarbon structures together. Thisbonding and cross-linking increases the molecular weight of the polymerproducts of the cross-linking reaction and increases the overall linkingdensity of the photoresist. Such an increase in density and linkingdensity helps to improve the resist pattern.

In some embodiments the cross-linking agent has the following structure:

wherein C is carbon, n ranges from 1 to 15; A and B independentlyinclude a hydrogen atom, a hydroxyl group, a halide, an aromatic carbonring, or a straight or cyclic alkyl, alkoxyl/fluoro, alkyl/fluoroalkoxylchain having a carbon number of between 1 and 12, and each carbon Ccontains A and B; a first terminal carbon C at a first end of a carbon Cchain includes X and a second terminal carbon C at a second end of thecarbon chain includes Y, wherein X and Y independently include an aminegroup, a thiol group, a hydroxyl group, an isopropyl alcohol group, oran isopropyl amine group, except when n=1 then X and Y are bonded to thesame carbon C. Specific examples of materials that may be used as thecross-linking agent include the following:

Alternatively, instead of or in addition to the cross-linking agentbeing added to the photoresist composition, a coupling reagent is addedin some embodiments, in which the coupling reagent is added in additionto the cross-linking agent. The coupling reagent assists thecross-linking reaction by reacting with the groups on the hydrocarbonstructure in the polymer resin before the cross-linking reagent,allowing for a reduction in the reaction energy of the cross-linkingreaction and an increase in the rate of reaction. The bonded couplingreagent then reacts with the cross-linking agent, thereby coupling thecross-linking agent to the polymer resin.

Alternatively, in some embodiments in which the coupling reagent isadded to the photoresist 12 without the cross-linking agent, thecoupling reagent is used to couple one group from one of the hydrocarbonstructures in the polymer resin to a second group from a separate one ofthe hydrocarbon structures in order to cross-link and bond the twopolymers together. However, in such an embodiment the coupling reagent,unlike the cross-linking agent, does not remain as part of the polymer,and only assists in bonding one hydrocarbon structure directly toanother hydrocarbon structure.

In some embodiments, the coupling reagent has the following structure:

where R is a carbon atom, a nitrogen atom, a sulfur atom, or an oxygenatom; M includes a chlorine atom, a bromine atom, an iodine atom, —NO₂;—SO₃—; —H—; —CN; —NCO, —OCN; —CO₂—; —OH; —OR*, —OC(O)CR*; —SR,—SO₂N(R*)₂; —SO₂R*; SOR; —OC(O)R*; —C(O)OR*; —C(O)R*; —Si(OR*)₃;—Si(R*)₃; epoxy groups, or the like; and R* is a substituted orunsubstituted C1-C12 alkyl, C1-C12 aryl, C1-C12 aralkyl, or the like.Specific examples of materials used as the coupling reagent in someembodiments include the following:

The individual components of the photoresist are placed into a solventin order to aid in the mixing and dispensing of the photoresist. To aidin the mixing and dispensing of the photoresist, the solvent is chosenat least in part based upon the materials chosen for the polymer resinas well as PACs or other additives. In some embodiments, the solvent ischosen such that the polymer resin and additives can be evenly dissolvedinto the solvent and dispensed upon the layer to be patterned.

Another additive added to some embodiments of the photoresist is astabilizer, which assists in preventing undesired diffusion of the acidsgenerated during exposure of the photoresist. In some embodiments, thestabilizer includes nitrogenous compounds, including aliphatic primary,secondary, and tertiary amines; cyclic amines, including piperidines,pyrrolidines, morpholines; aromatic heterocycles, including pyridines,pyrimidines, purines; imines, including diazabicycloundecene,guanidines, imides, amides, or the like. Alternatively, ammonium saltsare also be used for the stabilizer in some embodiments, includingammonium, primary, secondary, tertiary, and quaternary alkyl- andaryl-ammonium salts of alkoxides, including hydroxide, phenolates,carboxylates, aryl and alkyl sulfonates, sulfonamides, or the like.Other cationic nitrogenous compounds, including pyridinium salts andsalts of other heterocyclic nitrogenous compounds with anions, such asalkoxides, including hydroxide, phenolates, carboxylates, aryl and alkylsulfonates, sulfonamides, or the like, are used in some embodiments.

Another additive in some embodiments of the photoresist is a dissolutioninhibitor to help control dissolution of the photoresist duringdevelopment. In an embodiment bile-salt esters may be utilized as thedissolution inhibitor. Specific examples of dissolution inhibitors insome embodiments include cholic acid, deoxycholic acid, lithocholicacid, t-butyl deoxycholate, t-butyl lithocholate, and t-butyl-3-acetyllithocholate.

Another additive in some embodiments of the photoresist is aplasticizer. Plasticizers may be used to reduce delamination andcracking between the photoresist and underlying layers (e.g., the layerto be patterned). Plasticizers include monomeric, oligomeric, andpolymeric plasticizers, such as oligo- and polyethyleneglycol ethers,cycloaliphatic esters, and non-acid reactive steroidaly-derivedmaterials. Specific examples of materials used for the plasticizer insome embodiments include dioctyl phthalate, didodecyl phthalate,triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresylphosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerine, orthe like.

A coloring agent is another additive included in some embodiments of thephotoresist. The coloring agent observers examine the photoresist andfind any defects that may need to be remedied prior to furtherprocessing. In some embodiments, the coloring agent is a triarylmethanedye or a fine particle organic pigment. Specific examples of materialsin some embodiments include crystal violet, methyl violet, ethyl violet,oil blue #603, Victoria Pure Blue BOH, malachite green, diamond green,phthalocyanine pigments, azo pigments, carbon black, titanium oxide,brilliant green dye (C. I. 42020), Victoria Pure Blue FGA (Linebrow),Victoria BO (Linebrow) (C. I. 42595), Victoria Blue BO (C. I. 44045),rhodamine 6G (C. I. 45160), benzophenone compounds, such as2,4-dihydroxybenzophenone and 2,2′,4,4′-tetrahydroxybenzophenone;salicylic acid compounds, such as phenyl salicylate and 4-t-butylphenylsalicylate; phenylacrylate compounds, such asethyl-2-cyano-3,3-diphenylacrylate, and2′-ethylhexyl-2-cyano-3,3-diphenylacrylate; benzotriazole compounds,such as 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, and2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole;coumarin compounds, such as 4-methyl-7-diethylamino-1-benzopyran-2-one;thioxanthone compounds, such as diethylthioxanthone; stilbene compounds,naphthalic acid compounds, azo dyes, phthalocyanine blue, phthalocyaninegreen, iodine green, Victoria blue, crystal violet, titanium oxide,naphthalene black, Photopia methyl violet, bromphenol blue andbromcresol green; laser dyes, such as Rhodamine G6, Coumarin 500, DCM(4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H pyran)),Kiton Red 620, Pyrromethene 580, or the like. Additionally, one or morecoloring agents may be used in combination to provide the desiredcoloring.

Adhesion additives are added to some embodiments of the photoresist topromote adhesion between the photoresist and an underlying layer uponwhich the photoresist has been applied (e.g., the layer to bepatterned). In some embodiments, the adhesion additives include a silanecompound with at least one reactive substituent such as a carboxylgroup, a methacryloyl group, an isocyanate group and/or an epoxy group.Specific examples of the adhesion components include trimethoxysilylbenzoic acid, γ-methacryloxypropyl trimethoxy silane,vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltriethoxy silane, γ-glycidoxypropyl trimethoxy silane,β-(3,4-epoxycyclohexyl)ethyl trimethoxy silane, benzimidazoles andpolybenzimidazoles, a lower hydroxyalkyl substituted pyridinederivative, a nitrogen heterocyclic compound, urea, thiourea, anorganophosphorus compound, 8-oxyquinoline, 4-hydroxypteridine andderivatives, 1,10-phenanthroline and derivatives, 2,2′-bipyridine andderivatives, benzotriazoles, organophosphorus compounds,phenylenediamine compounds, 2-amino-1-phenylethanol,N-phenylethanolamine, N-ethyldiethanolamine, N-ethylethanolamine andderivatives, benzothiazole, and a benzothiazoleamine salt having acyclohexyl ring and a morpholine ring,3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane,3-methacryloyloxypropyltrimethoxysilane, vinyl trimethoxysilane,combinations thereof, or the like.

Surface leveling agents are added to some embodiments of the photoresistto assist a top surface of the photoresist to be level, so thatimpinging light will not be adversely modified by an unlevel surface. Insome embodiments, surface leveling agents include fluoroaliphaticesters, hydroxyl terminated fluorinated polyethers, fluorinated ethyleneglycol polymers, silicones, acrylic polymer leveling agents,combinations thereof, or the like.

In some embodiments, the polymer, along with any desired additives orother agents, are added to the solvent for application. Once added, themixture is then mixed in order to achieve a homogenous compositionthroughout the photoresist to ensure that there are no defects caused byuneven mixing or nonhomogenous composition of the photoresist. Oncemixed together, the photoresist may either be stored prior to its usageor used immediately.

Once ready, the photoresist is applied onto the layer to be patterned,as shown in FIG. 2, such as the substrate 10 to form a photoresist layer15. In some embodiments, the photoresist is applied using a process suchas a spin-on coating process, a dip coating method, an air-knife coatingmethod, a curtain coating method, a wire-bar coating method, a gravurecoating method, a lamination method, an extrusion coating method,combinations of these, or the like. In some embodiments, the photoresistlayer 15 thickness ranges from about 10 nm to about 300 nm.

After the photoresist layer 15 has been applied to the substrate 10, apre-bake of the photoresist layer is performed in some embodiments tocure and dry the photoresist prior to radiation exposure (see FIG. 1).The curing and drying of the photoresist layer 15 removes the solventcomponent while leaving behind the polymer resin, and the other chosenadditives, including a PAC, or cross-linking agent. In some embodiments,the pre-baking is performed at a temperature suitable to evaporate thesolvent, such as between about 40° C. and 120° C., although the precisetemperature depends upon the materials chosen for the photoresist. Thepre-baking is performed for a time sufficient to cure and dry thephotoresist layer, such as between about 10 seconds to about 10 minutes.

FIGS. 3A and 3B illustrate selective exposures of the photoresist layerto form an exposed region 50 and an unexposed region 52. In someembodiments, the exposure to radiation is carried out by placing thephotoresist-coated substrate in a photolithography tool. Thephotolithography tool includes a photomask 30/65, optics, an exposureradiation source to provide the radiation 45/97 for exposure, and amovable stage for supporting and moving the substrate under the exposureradiation.

In some embodiments, the radiation source (not shown) supplies radiation45/97, such as ultraviolet light, to the photoresist layer 15 in orderto induce a reaction of the PAG group or PACs, which in turn reacts withthe polymer resin to chemically alter those regions of the photoresistlayer to which the radiation 45/97 impinges. In some embodiments, theradiation is electromagnetic radiation, such as g-line (wavelength ofabout 436 nm), i-line (wavelength of about 365 nm), ultravioletradiation, far ultraviolet radiation, extreme ultraviolet, electronbeams, or the like. In some embodiments, the radiation source isselected from the group consisting of a mercury vapor lamp, xenon lamp,carbon arc lamp, a KrF excimer laser light (wavelength of 248 nm), anArF excimer laser light (wavelength of 193 nm), an F₂ excimer laserlight (wavelength of 157 nm), or a CO₂ laser-excited Sn plasma (extremeultraviolet, wavelength of 13.5 nm).

In some embodiments, optics (not shown) are used in the photolithographytool to expand, reflect, or otherwise control the radiation before orafter the radiation 45/97 is patterned by the photomask 30/65. In someembodiments, the optics include one or more lenses, mirrors, filters,and combinations thereof to control the radiation 45/97 along its path.

In some embodiments, the exposure of the photoresist layer 15 uses animmersion lithography technique. In such a technique, an immersionmedium (not shown) is placed between the final optics and thephotoresist layer, and the exposure radiation 45 passes through theimmersion medium.

After the photoresist layer 15 has been exposed to the exposureradiation 45, a post-exposure baking is performed in some embodiments toassist in the generating, dispersing, and reacting of the acid generatedfrom the impingement of the radiation 45 upon the PAG group or PACadditives during the exposure. Such thermal assistance helps to createor enhance chemical reactions, which generate chemical differencesbetween the exposed region 50 and the unexposed region 52 within thephotoresist layer 15. These chemical differences also cause differencesin the solubility between the exposed region 50 and the unexposed region52. In some embodiments, the post-exposure baking occurs at temperaturesranging from about 50° C. to about 160° C. for a period of between about20 seconds and about 10 minutes.

The inclusion of the cross-linking agent into the photoresistcomposition in some embodiments helps the components of the polymerresin (e.g., the individual polymers) react and bond with each other,increasing the molecular weight of the bonded polymer. In someembodiments, an initial polymer has a side chain with a carboxylic acidprotected by one of the groups to be removed/acid labile groups. Thegroups to be removed are removed in a de-protecting reaction, which isinitiated by a proton H⁺ generated by, e.g., the photoacid generatorduring either the exposure process or during the post-exposure bakingprocess. The H⁺ first removes the groups to be removed/acid labilegroups and another hydrogen atom may replace the removed structure toform a de-protected polymer. Once de-protected, a cross-linking reactionoccurs between two separate de-protected polymers that have undergonethe de-protecting reaction and the cross-linking agent in across-linking reaction. In particular, hydrogen atoms within thecarboxylic groups formed by the de-protecting reaction are removed andthe oxygen atoms react with and bond with the cross-linking agent. Thisbonding of the cross-linking agent to two polymers bonds the twopolymers not only to the cross-linking agent but also bonds the twopolymers to each other through the cross-linking agent, thereby forminga cross-linked polymer.

By increasing the molecular weight of the polymers through thecross-linking reaction, the new cross-linked polymer becomes lesssoluble in conventional organic solvent negative resist developers.

In some embodiments, the photoresist developer 57 includes a solvent,and an acid or a base. In some embodiments, the concentration of thesolvent in the developer is from about 60 wt. % to about 99 wt. % basedon the total weight of the photoresist developer. The acid or baseconcentration is from about 0.001 wt. % to about 20 wt. % based on thetotal weight of the photoresist developer. In certain embodiments, theacid or base concentration in the developer is from about 0.01 wt. % toabout 15 wt. % based on the total weight of the photoresist developer.

In some embodiments, the developer 57 is applied to the photoresistlayer 15 using a spin-on process. In the spin-on process, the developer57 is applied to the photoresist layer 15 from above the photoresistlayer 15 while the photoresist-coated substrate is rotated, as shown inFIG. 4. In some embodiments, the developer 57 is supplied at a rate ofbetween about 5 ml/min and about 800 ml/min, while the photoresistcoated substrate 10 is rotated at a speed of between about 100 rpm andabout 2000 rpm. In some embodiments, the developer is at a temperatureof between about 10° C. and about 80° C. The development operationcontinues for between about 30 seconds to about 10 minutes in someembodiments.

While the spin-on operation is one suitable method for developing thephotoresist layer 15 after exposure, it is intended to be illustrativeand is not intended to limit the embodiment. Rather, any suitabledevelopment operations, including dip processes, puddle processes, andspray-on methods, may alternatively be used. All such developmentoperations are included within the scope of the embodiments.

During the development process, the developer 57 dissolves theradiation-exposed regions 50 of the positive tone resist, exposing thesurface of the substrate 10, as shown in FIG. 5, and leaving behindwell-defined unexposed photoresist regions 52, having improveddefinition than provided by conventional photoresist photolithography.

After the developing operation S150, remaining developer is removed fromthe patterned photoresist covered substrate. The remaining developer isremoved using a spin-dry process in some embodiments, although anysuitable removal technique may be used. After the photoresist layer 15is developed, and the remaining developer is removed, additionalprocessing is performed while the patterned photoresist layer 52 is inplace. For example, an etching operation, using dry or wet etching, isperformed in some embodiments, to transfer the pattern of thephotoresist layer 52 to the underlying substrate 10, forming recesses55′ as shown in FIG. 6. The substrate 10 has a different etch resistancethan the photoresist layer 15. In some embodiments, the etchant is moreselective to the substrate 10 than the photoresist layer 15.

In some embodiments, the substrate 10 and the photoresist layer 15contain at least one etching resistance molecule. In some embodiments,the etching resistant molecule includes a molecule having a low Onishinumber structure, a double bond, a triple bond, silicon, siliconnitride, titanium, titanium nitride, aluminum, aluminum oxide, siliconoxynitride, combinations thereof, or the like.

In some embodiments, a layer to be patterned 60 is disposed over thesubstrate prior to forming the photoresist layer, as shown in FIG. 12.In some embodiments, the layer to be patterned 60 is a metallizationlayer or a dielectric layer, such as a passivation layer, disposed overa metallization layer. In embodiments where the layer to be patterned 60is a metallization layer, the layer to be patterned 60 is formed of aconductive material using metallization processes, and metal depositiontechniques, including chemical vapor deposition, atomic layerdeposition, and physical vapor deposition (sputtering). Likewise, if thelayer to be patterned 60 is a dielectric layer, the layer to bepatterned 60 is formed by dielectric layer formation techniques,including thermal oxidation, chemical vapor deposition, atomic layerdeposition, and physical vapor deposition.

The photoresist layer 50 is subsequently selectively exposed to actinicradiation 45 to form exposed regions 50 and unexposed regions 52 in thephotoresist layer, as shown in FIGS. 13A and 13B, and described hereinin relation to FIGS. 3A and 3B. As explained herein the photoresist is anegative photoresist, wherein polymer crosslinking occurs in the exposedregions 50 in some embodiments.

As shown in FIG. 14, the exposed photoresist regions 50 are developed bydispensing developer 57 from a dispenser 62 to form a pattern ofphotoresist openings 55, as shown in FIG. 15. The development operationis similar to that explained with reference to FIGS. 4 and 5, herein.

Then as shown in FIG. 16, the pattern 55 in the photoresist layer 15 istransferred to the layer to be patterned 60 using an etching operationand the photoresist layer is removed, as explained with reference toFIG. 6 to form pattern 55″ in the layer to be patterned 60.

Other embodiments include other operations before, during, or after theoperations described above. In some embodiments, the disclosed methodsinclude forming semiconductor devices, including fin field effecttransistor (FinFET) structures. In some embodiments, a plurality ofactive fins are formed on the semiconductor substrate. Such embodiments,further include etching the substrate through the openings of apatterned hard mask to form trenches in the substrate; filling thetrenches with a dielectric material; performing a chemical mechanicalpolishing (CMP) process to form shallow trench isolation (STI) features;and epitaxy growing or recessing the STI features to form fin-likeactive regions. In some embodiments, one or more gate electrodes areformed on the substrate. Some embodiments include forming gate spacers,doped source/drain regions, contacts for gate/source/drain features,etc. In other embodiments, a target pattern is formed as metal lines ina multilayer interconnection structure. For example, the metal lines maybe formed in an inter-layer dielectric (ILD) layer of the substrate,which has been etched to form a plurality of trenches. The trenches maybe filled with a conductive material, such as a metal; and theconductive material may be polished using a process such as chemicalmechanical planarization (CMP) to expose the patterned ILD layer,thereby forming the metal lines in the ILD layer. The above arenon-limiting examples of devices/structures that can be made and/orimproved using the method described herein.

In some embodiments, active components such diodes, field-effecttransistors (FETs), metal-oxide semiconductor field effect transistors(MOSFET), complementary metal-oxide semiconductor (CMOS) transistors,bipolar transistors, high voltage transistors, high frequencytransistors, FinFETs, other three-dimensional (3D) FETs, metal-oxidesemiconductor field effect transistors (MOSFET), complementarymetal-oxide semiconductor (CMOS) transistors, bipolar transistors, highvoltage transistors, high frequency transistors, other memory cells, andcombinations thereof are formed, according to embodiments of thedisclosure.

The novel compositions, photolithographic patterning methods, andsemiconductor manufacturing methods according to the present disclosureprovide higher semiconductor device feature resolution and density athigher wafer exposure throughput with reduced defects in a higherefficiency process than conventional patterning techniques. The novelphotoresist compositions and methods provide improved etching resistanceof the photoresist layer.

An embodiment of the disclosure is a method of forming a pattern in aphotoresist layer, including forming a photoresist layer over asubstrate, and selectively exposing the photoresist layer to actinicradiation to form a latent pattern. The latent pattern is developed byapplying a developer to the selectively exposed photoresist layer toform a pattern. The photoresist layer includes a photoresist compositioncomprising a polymer, wherein the polymer has a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1. In an embodiment, A₁,A₂, and A₃ are independently a chain, ring, or three-dimensionalstructure. In an embodiment, at least one of A₁, A₂, and A₃ is athree-dimensional adamantyl or norbornyl structure. In an embodiment, R₁is a C4-C15 alkyl group, a C4-C15 cycloalkyl group, a C4-C15hydroxylalkyl group, a C4-C15 alkoxy group, or a C4-C15 alkoxyl alkylgroup. In an embodiment, the photoacid generator includes atriphenylsulfonium group and a sulfonate group. In an embodiment, R_(f)is a perfluorinated group. In an embodiment, A₃ is a phenol group, ahydroxynaphthalene group, or a hydroxyanthracene group. In anembodiment, A₁, A₂, and A₃ are independently a phenyl group or anaphthalenyl group. In an embodiment, L is a direct bond and A₃ is ap-phenol group, and 0.2≤x/(x+y+z)≤0.5. In an embodiment, A₁ is not adirect bond and 0.2≤y/(x+y+z)≤0.7. In an embodiment, the photoresistcomposition includes a solvent. In an embodiment, the polymer has aweight average molecular weight ranging from 500 to 1,000,000. In anembodiment, the polymer has a weight average molecular weight rangingfrom 2,000 to 250,000. In an embodiment, the photoresist compositionincludes a photoactive compound. In an embodiment, the photoactivecompound is a photoacid generator. In an embodiment, A₂ is not a directbond and 0.05≤z/(x+y+z)≤0.5. In an embodiment, 0.1≤x/(x+y+z)≤0.5. In anembodiment, A₁ and A₂ are not direct bonds and 0.2≤y/(x+y+z)≤0.7 and0.05≤z/(x+y+z)≤0.5. In an embodiment, A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. In an embodiment, A₁ and A₂ arenot direct bonds and 0.2≤y/(x+y+z)≤0.7, 0.05≤z/(x+y+z)≤0.5, and0.1≤x/(x+y+z)≤0.5. In an embodiment, the photoresist compositionincludes a photoactive compound, A₁ is not a direct bond, and0.2≤y/(x+y+z)≤0.7. In an embodiment, the photoresist compositionincludes a photoactive compound and 0.1≤x/(x+y+z)≤0.5. In an embodiment,the photoresist composition includes a photoactive compound, A₁ is not adirect bond and 0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. In anembodiment, the photoresist composition includes a metal oxidenanoparticle and one or more organic ligands. In an embodiment, theactinic radiation is extreme ultraviolet radiation. In an embodiment,the method includes after selectively exposing the photoresist layer toactinic radiation to form a latent pattern and before developing thelatent pattern heating the photoresist layer. In an embodiment, themethod includes heating the photoresist layer before selectivelyexposing the photoresist layer to actinic radiation to form a latentpattern.

Another embodiment of the disclosure is a method of manufacturing asemiconductor device, including forming a photoresist layer over asubstrate. The photoresist layer includes a photoresist composition,including a polymer having a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1. A latent pattern isformed in the photoresist layer by patternwise exposing the photoresistlayer to actinic radiation. A developer is applied to the patternwiseexposed photoresist layer to form a pattern exposing a portion of thesubstrate. The pattern is extended into substrate. In an embodiment, theextending the pattern into the substrate includes etching the substrate.In an embodiment, the method includes heating the photoresist layer at atemperature of 50° C. to 160° C. after the forming a latent pattern andbefore the applying a developer. In an embodiment, the method includesheating the photoresist layer at a temperature of 40° C. to 120° C.before the forming a latent pattern. In an embodiment, the actinicradiation is extreme ultraviolet radiation.

Another embodiment of the disclosure is a photoresist composition,including a polymer, wherein the polymer has a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1. In an embodiment, A₁,A₂, and A₃ are independently a chain, ring, or three-dimensionalstructure. In an embodiment, at least one of A₁, A₂, and A₃ is athree-dimensional structure selected from an adamantyl or norbornylstructure. In an embodiment, R₁ is a C4-C15 alkyl group, a C4-C15cycloalkyl group, a C4-C15 hydroxylalkyl group, a C4-C15 alkoxy group,or a C4-C15 alkoxyl alkyl group. In an embodiment, the photoacidgenerator includes a triphenylsulfonium group and a sulfonate group. Inan embodiment, R_(f) is a perfluorinated group. In an embodiment, A₃ isa phenol group, a hydroxynaphthalene group, or a hydroxyanthracenegroup. In an embodiment, A₁, A₂, and A₃ are independently a phenyl groupor a naphthalenyl group. In an embodiment, the photoresist compositionincludes a solvent. In an embodiment, the polymer has a weight averagemolecular weight ranging from 500 to 1,000,000. In an embodiment, thepolymer has a weight average molecular weight ranging from 2,000 to250,000. In an embodiment, the photoresist composition includes aphotoactive compound. In an embodiment, the photoactive compound is aphotoacid generator. In an embodiment, L is a direct bond, A₃ is ap-phenol group, and 0.2≤x/(x+y+z)≤0.5. In an embodiment, A₁ is not adirect bond and 0.2≤y/(x+y+z)≤0.7. In an embodiment, A₂ is not a directbond and 0.05≤z/(x+y+z)≤0.5. In an embodiment, 0.1≤x/(x+y+z)≤0.5. In anembodiment, A₁ and A₂ are not direct bonds and 0.2≤y/(x+y+z)≤0.7 and0.05≤z/(x+y+z)≤0.5. In an embodiment, A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. In an embodiment, A₁ and A₂ arenot direct bonds and 0.2≤y/(x+y+z)≤0.7, 0.05≤z/(x+y+z)≤0.5, and0.1≤x/(x+y+z)≤0.5. In an embodiment, the photoresist compositionincludes a photoactive compound, A₁ is not a direct bond, and0.2≤y/(x+y+z)≤0.7. In an embodiment, the photoresist compositionincludes a photoactive compound, wherein 0.1≤x/(x+y+z)≤0.5. In anembodiment, the photoresist composition includes a photoactive compound,A₁ is not a direct bond, and 0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. Inan embodiment, the photoresist composition includes a metal oxidenanoparticle and one or more organic ligands.

Another embodiment of the disclosure is a method of patterning aphotoresist layer, including depositing a photoresist layer over asubstrate. A latent pattern is formed in the photoresist layer byselectively exposing the photoresist layer to actinic radiation. Aportion of the selectively exposed photoresist layer is removed byapplying a developer to the selectively exposed photoresist layer toform a pattern in the photoresist layer. The photoresist layer includesa photoresist composition including a polymer, wherein the polymer has aformula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0<x/(x+y+z)<1, 0<y/(x+y+z)<1, and 0<z/(x+y+z)<1. In an embodiment, aportion of the photoresist layer that is exposed to the actinicradiation is the portion of the selectively exposed photoresist layerremoved by applying the developer. In an embodiment, A₁, A₂, and A₃ areindependently a chain, ring, or three-dimensional structure. In anembodiment, at least one of A₁, A₂, and A₃ is a three-dimensionalstructure selected from an adamantyl or norbornyl structure. In anembodiment, R₁ is a C4-C15 alkyl group, a C4-C15 cycloalkyl group, aC4-C15 hydroxylalkyl group, a C4-C15 alkoxy group, or a C4-C15 alkoxylalkyl group. In an embodiment, the photoacid generator includes atriphenylsulfonium group and a sulfonate group. In an embodiment, R_(f)is a perfluorinated group. In an embodiment, A₃ is a phenol group, ahydroxynaphthalene group, or a hydroxyanthracene group. In anembodiment, A₁, A₂, and A₃ are independently a phenyl group or anaphthalenyl group. In an embodiment, L is a direct bond and A₃ is ap-phenol group, and 0.2≤x/(x+y+z)≤0.5. In an embodiment, A₁ is not adirect bond and 0.2≤y/(x+y+z)≤0.7. In an embodiment, 0.1≤x/(x+y+z)≤0.5.In an embodiment, A₁ and A₂ are not direct bonds and 0.2≤y/(x+y+z)≤0.7and 0.05≤z/(x+y+z)≤0.5. In an embodiment, A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. In an embodiment, A₁ and A₂ arenot direct bonds and 0.2≤y/(x+y+z)≤0.7, 0.05≤z/(x+y+z)≤0.5, and0.1≤x/(x+y+z)≤0.5. In an embodiment, the photoresist compositionincludes a photoactive compound, A₁ is not a direct bond, and0.2≤y/(x+y+z)≤0.7. In an embodiment, the photoresist compositionincludes a photoactive compound and 0.1≤x/(x+y+z)≤0.5. In an embodiment,the photoresist composition includes a photoactive compound, A₁ is not adirect bond, and 0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5.

Another embodiment of the disclosure is a photoresist composition,including a polymer, wherein the polymer has a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0<x/(x+y+z)<1, 0<y/(x+y+z)<1, and 0<z/(x+y+z)<1. In an embodiment, A₁,A₂, and A₃ are independently a chain, ring, or three-dimensionalstructure. In an embodiment, at least one of A₁, A₂, and A₃ is athree-dimensional structure selected from an adamantyl or norbornylstructure. In an embodiment, R₁ is a C4-C15 alkyl group, a C4-C15cycloalkyl group, a C4-C15 hydroxylalkyl group, a C4-C15 alkoxy group,or a C4-C15 alkoxyl alkyl group. In an embodiment, the photoacidgenerator includes a triphenylsulfonium group and a sulfonate group. Inan embodiment, R_(f) is a perfluorinated group. In an embodiment, A₃ isa phenol group, a hydroxynaphthalene group, or a hydroxyanthracenegroup. In an embodiment, A₁, A₂, and A₃ are independently a phenyl groupor a naphthalenyl group. In an embodiment, the photoresist compositionincludes a solvent. In an embodiment, the polymer has a weight averagemolecular weight ranging from 500 to 1,000,000. In an embodiment, thepolymer has a weight average molecular weight ranging from 2,000 to250,000. In an embodiment, the photoresist composition includes aphotoactive compound. In an embodiment, the photoactive compound is aphotoacid generator. In an embodiment, L is a direct bond, A₃ is ap-phenol group, and 0.2≤x/(x+y+z)≤0.5. In an embodiment, A₁ is not adirect bond and 0.2≤y/(x+y+z)≤0.7. In an embodiment, A₂ is not a directbond and 0.05≤z/(x+y+z)≤0.5. In an embodiment, 0.1≤x/(x+y+z)≤0.5. In anembodiment, A₁ and A₂ are not direct bonds and 0.2≤y/(x+y+z)≤0.7 and0.05≤z/(x+y+z)≤0.5. In an embodiment, A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. In an embodiment, A₁ and A₂ arenot direct bonds and 0.2≤y/(x+y+z)≤0.7, 0.05≤z/(x+y+z)≤0.5, and0.1≤x/(x+y+z)≤0.5. In an embodiment, the photoresist compositionincludes a photoactive compound, A₁ is not a direct bond, and0.2≤y/(x+y+z)≤0.7. In an embodiment, the photoresist compositionincludes a photoactive compound and 0.1≤x/(x+y+z)≤0.5. In an embodiment,the photoresist composition includes a photoactive compound, A₁ is not adirect bond, and 0.2≤y/(x+y+z)≤0.7 and 0.1≤x/(x+y+z)≤0.5. In anembodiment, the photoresist composition includes a metal oxidenanoparticle and one or more organic ligands.

Another embodiment of the disclosure is a polymer composition, includinga polymer having a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; wherein at least one ofA₁, A₂, and A₃ is an adamantyl group, a norbornyl group, a phenol group,a hydroxynaphthalene group, a hydroxyanthracene group, a phenyl group,or a naphthalenyl group; R₁ is an acid labile group; Ra and Rb areindependently H or a C1-C3 alkyl group; R_(f) is a direct bond or aC1-C5 fluorocarbon; PAG includes a triphenylsulfonium group and asulfonate group; and 0<x/(x+y+z)<1, 0<y/(x+y+z)<1, and 0<z/(x+y+z)<1. Inan embodiment, R₁ is a C4-C15 alkyl group, a C4-C15 cycloalkyl group, aC4-C15 hydroxylalkyl group, a C4-C15 alkoxy group, or a C4-C15 alkoxylalkyl group. In an embodiment, R_(f) is a perfluorinated group. In anembodiment, the polymer has a weight average molecular weight rangingfrom 500 to 1,000,000. In an embodiment, the polymer has a weightaverage molecular weight ranging from 2,000 to 250,000. In anembodiment, L is a direct bond, A₃ is a p-phenol group, and0.2≤x/(x+y+z)≤0.5. In an embodiment, A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7. In an embodiment, A₂ is not a direct bond and0.05≤z/(x+y+z)≤0.5. In an embodiment, 0.1≤x/(x+y+z)≤0.5. In anembodiment, A₁ and A₂ are not direct bonds, 0.2≤y/(x+y+z)≤0.7, and0.05≤z/(x+y+z)≤0.5. In an embodiment, A₁ is not a direct bond,0.2≤y/(x+y+z)≤0.7, and 0.1≤x/(x+y+z)≤0.5. In an embodiment, A₁ and A₂are not direct bonds, 0.2≤y/(x+y+z)≤0.7, 0.05≤z/(x+y+z)≤0.5, and0.1≤x/(x+y+z)≤0.5.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A method of forming a pattern in a photoresistlayer, comprising: forming a photoresist layer over a substrate;selectively exposing the photoresist layer to actinic radiation to forma latent pattern; and developing the latent pattern by applying adeveloper to the selectively exposed photoresist layer to form apattern, wherein the photoresist layer includes a photoresistcomposition comprising a polymer, wherein the polymer has a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA₁ and A₂ are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1.
 2. The method accordingto claim 1, wherein A₁, A₂, and A₃ are independently a chain, ring, orthree-dimensional structure.
 3. The method according to claim 2, whereinat least one of A₁, A₂, and A₃ is a three-dimensional adamantyl ornorbornyl structure.
 4. The method according to claim 1, wherein R₁ is aC4-C15 alkyl group, a C4-C15 cycloalkyl group, a C4-C15 hydroxylalkylgroup, a C4-C15 alkoxy group, or a C4-C15 alkoxyl alkyl group.
 5. Themethod according to claim 1, wherein the photoacid generator includes atriphenylsulfonium group and a sulfonate group.
 6. The method accordingto claim 1, wherein R_(f) is a perfluorinated group.
 7. The methodaccording to claim 1, wherein A₃ is a phenol group, a hydroxynaphthalenegroup, or a hydroxyanthracene group.
 8. The method according to claim 1,wherein A₁, A₂, and A₃ are independently a phenyl group or anaphthalenyl group.
 9. The method according to claim 1, wherein L is adirect bond and A₃ is a p-phenol group, and 0.2≤x/(x+y+z)≤0.5.
 10. Themethod according to claim 1, wherein A₁ is not a direct bond and0.2≤y/(x+y+z)≤0.7.
 11. A method of manufacturing a semiconductor device,forming a photoresist layer over a substrate, wherein the photoresistlayer comprises a photoresist composition, comprising a polymer having aformula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA₁ and A₂ are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1; forming a latentpattern in the photoresist layer by patternwise exposing the photoresistlayer to actinic radiation; applying a developer to the patternwiseexposed photoresist layer to form a pattern exposing a portion of thesubstrate; and extending the pattern into substrate.
 12. The methodaccording to claim 11, wherein the extending the pattern into thesubstrate comprises etching the substrate.
 13. The method according toclaim 11, further comprising heating the photoresist layer at atemperature of 50° C. to 160° C. after the forming a latent pattern andbefore the applying a developer.
 14. The method according to claim 11,further comprising heating the photoresist layer at a temperature of 40°C. to 120° C. before the forming a latent pattern.
 15. The methodaccording to claim 11, wherein the actinic radiation is extremeultraviolet radiation.
 16. A photoresist composition, comprising: apolymer, wherein the polymer has a formula:

where A₁, A₂, and L are independently a direct bond, a C4-C30 aromaticgroup, a C4-C30 alkyl group, a C4-C30 cycloalkyl group, a C4-C30hydroxylalkyl group, a C4-C30 alkoxy group, a C4-C30 alkoxyl alkylgroup, a C4-C30 acetyl group, a C4-C30 acetylalkyl group, a C4-C30 alkylcarboxyl group, a C4-C30 cycloalkyl carboxyl group, a C4-C30 saturatedor unsaturated hydrocarbon ring, or a C4-C30 heterocyclic group, whereinA1 and A2 are not both direct bonds, wherein A₁ and A₂ are unsubstitutedor substituted with a halogen, carbonyl group, or hydroxyl group; A₃ isa C6-C14 aromatic group, wherein A₃ is unsubstituted or substituted witha halogen, carbonyl group, or hydroxyl group; R₁ is an acid labilegroup; Ra and Rb are independently H or a C1-C3 alkyl group; R_(f) is adirect bond or a C1-C5 fluorocarbon; PAG is a photoacid generator; and0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1.
 17. The photoresistcomposition of claim 16, wherein A₁, A₂, and A₃ are independently achain, ring, or three-dimensional structure.
 18. The photoresistcomposition of claim 17, wherein at least one of A₁, A₂, and A₃ is athree-dimensional structure selected from an adamantyl or a norbornylstructure.
 19. The photoresist composition of claim 16, wherein R₁ is aC4-C15 alkyl group, a C4-C15 cycloalkyl group, a C4-C15 hydroxylalkylgroup, a C4-C15 alkoxy group, or a C4-C15 alkoxyl alkyl group.
 20. Thephotoresist composition of claim 16, wherein the photoacid generatorincludes a triphenylsulfonium group and a sulfonate group.